Methods and systems for merging topics assigned to content items in an online application

ABSTRACT

A question-and-answer application having questions with which topics are associated is described. In some embodiments, user-generated topics are assigned to questions to indicate the subject matter covered by the questions. The application logic includes topic merge logic for quickly and efficiently merging two topics, while enabling the topic merge operation to be easily undone if necessary.

TECHNICAL FIELD

The present disclosure generally relates to data processing techniques.More specifically, the present disclosure relates to methods and systemsfor quickly and efficiently performing a topic merge operation to mergeinto a common topic two or more content items (e.g., questions) that areassigned to different topics.

BACKGROUND

A variety of web-based applications provide users with the ability tocollaboratively generate content, for example, by creating and/orediting web page components, or even entire web pages, via aconventional web browser application. Some web-based applications thatprovide such functionality are referred to as wikis. One particular typeof application that provides such functionality is a web-basedencyclopedia that allows users to generate and edit articles on varioustopics of interest. Another example of an application that relies oncollaborative, user-generated content is a question-and-answerapplication that provides an online forum that enables users to postquestions, post answers to questions, or simply view questions andcorresponding answers.

With this type of application, because the content is user-generated andoften several users may be contributing, it is often difficult toeffectively and efficiently maintain the content in an organized manner.For instance, with a web-based encyclopedia application, multiple usersmay generate articles for similar, or even the same, topic. As thenumber of article entries grows, it can become an extremely daunting andtime consuming task for a content administrator to manually identifywhat are essentially duplicate articles and then combine their content.Similarly, with a question-and-answer application, users may establishvarious topics or categories to which questions are assigned. When userscreate multiple topics for what is essentially the same subject matter,it may become difficult for users to quickly identify content ofinterest. For instance, if four or five synonymous topic names exist forthe same subject matter, such as, “San Francisco Bay Area,” “The BayArea,” “San Francisco, Calif.,” “San Francisco,” “The Greater Bay Area,”and so forth, it becomes difficult for a user to know which of theseveral topics to select to find relevant information. When differenttopic names are used for the same subject matter, it may be timeconsuming for a user to assign a particular question to all of therelevant topics. Moreover, as the number of topics associated with aparticular questions increases, the time required to process the dataand to identify and recall all of the topics associated with aparticular question may also increase, thereby introducing a delay intothe user experience.

DESCRIPTION OF THE DRAWINGS

Some embodiments of the invention are illustrated by way of example, andnot limitation, in the figures of the accompanying drawings, in which:

FIG. 1 is a simple relationship diagram illustrating how some of thevarious elements and participants of a question-and-answer applicationare related to one another in a particular embodiment of the invention;

FIG. 2 is a system-level block diagram illustrating some of the systemcomponents and functional modules used in implementing aquestion-and-answer application consistent with an embodiment of theinvention;

FIG. 3 shows some example data structures—in the form of databasetables—for use in implementing a question-and-answer applicationconsistent with an embodiment of the invention;

FIG. 4 is a user interface diagram illustrating an example of a userinterface for use with a question-and-answer application consistent withan embodiment of the invention;

FIG. 5 is a block diagram showing an example of how database tables canbe utilized in a topic merge operation to merge two topics with oneanother, consistent with an embodiment of the invention;

FIG. 6 is a flow diagram illustrating method operations involved in amethod to merge one topic with another, consistent with an embodiment ofthe invention;

FIG. 7 is a flow diagram illustrating method operations involved in amethod to identify and display topics associated with a content item,such as a question or answer in a question-and-answer application,according to an embodiment of the invention;

FIG. 8 is a flow diagram illustrating method operations involved inmethod for performing a “follow-merge” operation for use in identifyingtopics that have been merged into other topics, according to anembodiment of the invention;

FIG. 9 is a flow diagram illustrating method operations involved in amethod to identify content items (e.g., questions or users) to which aparticular topic is associated; and

FIG. 10 is a block diagram of a machine in the form of a computer withinwhich a set of instructions, for causing the machine to perform any oneor more of the methodologies discussed herein, may be executed.

DETAILED DESCRIPTION

Methods and systems for efficiently performing an operation to merge twodifferent topics are described. In the following description, forpurposes of explanation, numerous specific details are set forth inorder to provide a thorough understanding of the various aspects ofdifferent embodiments of the present invention. It will be evident,however, to one skilled in the art, that the present invention may bepracticed without these specific details.

Although a skilled artisan will readily appreciate the applicability ofthe described invention in a wide variety of applications and contexts,the inventive subject matter described herein is presented in thecontext of an online question-and-answer application. Aquestion-and-answer application provides an online forum where users canpost questions, post answers to questions, or simply search for andreview questions and answers that others have posted. As such, aquestion-and-answer application is an information repository ofuser-generated content that is organized and presented in a relativelysimple and intuitive manner. Consistent with some embodiments of theinvention, to further aid in the overall organization and presentationof information, a question can be associated with one or more topicsrepresenting, for example, a subject matter to which the questionrelates. Take for example the question, “What is the population of SanFrancisco?” This question may be assigned to the topic, “San Francisco.”As users post questions for others to answer, users can designate eachquestion as being related to one or more existing topics, or users cancreate and designate new topics.

As the amount of information relevant to a given subject matter grows,users may find it desirable to merge one topic with another topic. Forinstance, if separate topics exist for “San Francisco” and “SanFrancisco, Calif.,” it may be desirable to merge the two differenttopics into a single topic. Such an operation is described herein and isgenerally referred to as a topic merge operation. Consistent with anembodiment of the invention, a topic merge operation is a directionaloperation such that one topic is said to be “merged into” another topic.For instance, the topic, “San Francisco,” might be merged into thetopic, “San Francisco, Calif.” In such a scenario, subsequent to theprocessing of the topic merge operation, any question previouslyassociated with “San Francisco” will be associated with the topic, “SanFrancisco, Calif.” However, because a topic merge operation is adirectional operation, in this example a question that is associatedwith “San Francisco, Calif.” will not, as a result of the topic mergeoperation, automatically be associated with the topic, “San Francisco.”For purposes of the present disclosure, to distinguish between the topicthat is being merged, and the topic into which another topic is merged,the term “target topic” is used. For instance, if topic A is beingmerged into topic B, then topic B is referred to herein as the targettopic.

Consistent with some embodiments of the invention, the data structure ordata representation of a topic, and the topic merge logic used toperform a topic merge operation, are designed to operate efficiently.For purposes of the present invention, this means that topics can beeasily and quickly merged and unmerged, and recalling the topicsassociated with any particular content item (e.g., a question) isachieved rapidly with minimal processing. As will be described ingreater detail below, the topic merge logic ensures that no topic ismerged with another topic, if the other topic is itself merged with athird topic. For instance, if a user desires to merge a first topic(topic A) into a second topic (topic B), but the second topic is mergedwith a third topic (topic C), the topic merge logic prevents therequested merge operation, but instead will automatically merge thefirst topic with the third topic. In this example, the result of thetopic merge operation will be that topic A is automatically merged intotopic C. By preventing a topic from being merged into another topic thatis itself merged into a third topic, the need to process lengthy linkedlists, or perform several database table look-up operations, iseliminated. Instead, the depth of any linked data structure used forstoring merged topics is at most one level or link deep. This ensuresthat the processing time required to identify all topics that have beenassigned to or associated with a particular question, or to identify alltopics that a particular use is following, is predictably short.

In addition, the topic merge logic is designed to enable a user oradministrator to quickly and easily undo a topic merge operation (e.g.,unmerge two previously merged topics). This is particularly important inthe context of applications that are utilizing user-generated contentand enabling users to merge topics. As is the case with manyapplications relying on user-generated content, there is a significantlikelihood that there will be differences in opinion amongst users as tothe subject matter covered by a particular topic or category.Accordingly, because any user has the ability to merge two topics, it isvery advantageous to have a simple and easy mechanism for undoing atopic merge operation that is ultimately perceived to be undesirable orincorrect. Consistent with an embodiment of the invention, when a topicmerge operation is performed, the operation is logged so that it caneasily be undone. As will be described in greater detail below, becausea topic merge is achieved without creating long linked lists of topics,undoing a single merge operation is as simple as writing to a singlefield of a database or updating a single data structure member. Otheraspects of various embodiments of the invention are described below inconnection with the description of the figures.

FIG. 1 is a simple relationship diagram illustrating how some of thevarious elements and participants of a question-and-answer applicationare related to one another in a particular embodiment of the invention.For instance, as illustrated in FIG. 1, a user 10 of thequestion-and-answer application may follow another user 12, a topic 14,or a question 16. As used herein, the concept of “following” is somewhatanalogous to the concept of subscribing in a subscription-based model.In contrast to the concept of two users being “connected” (e.g., in asocial networking context), which typically implies a personalrelationship between the users, when a user follows another user, thereis no implied personal relationship between the two users. For instance,a first user may follow a second user simply because the first userbelieves the second user is particularly insightful with respect to aparticular topic of interest. By “following” another user, a user can beautomatically informed of activities of the other user. If, for example,user A is following user B, when user B posts a question or an answer toa question, user A will be notified of user B's posting activity.Similarly, if a user elects to follow a particular topic, as newquestions are assigned to the particular topic, the user can beautomatically notified of these new questions. In yet another example,if a user follows a particular question, as new answers are posted tothe particular question, the user will be notified of the new answers.

In some embodiments of the invention, notifications may be communicatedto a user by simply including the relevant content in a landing page ordata feed displayed to the user. For example, when a user first provideshis or her authentication information (e.g., username/password), theuser may be presented with a personalized home page or landing page withcontent that is customized for the user. This content may be selected toinclude information regarding the users, topics and questions that theparticular user is following. Additionally, in some embodiments,notifications may be communicated in near real-time to a user via anynumber of conventional and well-known messaging mechanisms, to includeemail, SMS or text messages, instant messages, and others. In someembodiments, a user may elect to be notified of certain activities orevents on a per-question, per-topic or per-user basis. For instance, auser may elect to receive an email notification anytime a new answer isposted to a particular question that the user has posted, and is thusfollowing by default.

Referring again to FIG. 1, a topic 14 may have a wiki summary 18 thatprovides a summary or some additional description of what subject matteris encompassed by the particular topic. Similarly, a question 16 mayhave a wiki summary 18 that provides some description or additionalcontext for the question. In some embodiments, the wiki summary 18 fortopics and questions may be user-editable by all users, while in otherembodiments, only certain users will have the authority to edit a wikisummary. For instance, in some embodiments, only the person who posted aparticular question may be authorized to edit the wiki summary for thatparticular question. In some embodiments, users may be assigned rolesthat determine various content or access privileges the users have withrespect to different topics or questions. For instance, certain usersmay be assigned an “editor” role for a particular topic, therebyproviding those users with editing privileges that are different fromthose of a regular user.

In addition to a wiki summary 18, a question 16 is associated with oneor more answers 20. For instance, after a user posts a question, otherusers of the application are able to provide answers to the question. Insome embodiments of the invention, any user is allowed to post an answerto a particular question. As such, a question may be associated with orhave multiple answers. In some embodiments, both questions 16 andanswers 20 may have comments. For instance, a user may provide a textualcomment that is associated with a question 16 or an answer 20. A commentassociated with an answer, for example, could provide some clarificationabout a particular answer, or some aspect of the answer. Other users canthen view the comments when viewing the question and/or answers.

In some embodiments of the invention, an answer 20 has or is associatedwith votes 24. For example, users can vote up or vote down a particularanswer based on whether the user finds the answer helpful in view of theparticular question. For instance, if a user believes that a particularanswer to a question is a good answer, the user can select a button orother graphical user interface element to vote for the answer.Similarly, if a user believes that a particular answer is not helpful inlight of the question, the user can vote down the answer, for example,by simply selecting a button or other graphical user interface elementto indicate that the answer is not helpful. In some embodiments, thenumber of votes for and against an answer are used as inputs to analgorithm that determines how answers are to be displayed when presentedto a user. For example, the votes for and against an answer may simplybe tallied, such that a vote for the answer offsets a vote against theanswer, and the answers with the highest vote tallies are displayed inthe most prominent positions—typically, at the top of a list of relevantanswers.

By providing a forum that includes questions, answers, comments andvotes, the question-and-answer application encourages meaningfuldiscussion about a whole host of subject matters, in part, by enablingusers to interact with the application in a variety of ways. Forinstance, some user may desire an entirely passive experience, and cantherefore simply browse for, and read, questions and answers on topicsof interest. Some users may desire an experience including a moderatelevel of participation, and as such, these users can vote up or downvarious answers on topics of interest, and possibly provide commentary.Others may desire to participate more actively, and will elect to postquestions and answers to questions.

FIG. 2 is a system-level block diagram illustrating some of the systemcomponents and functional modules used in implementing aquestion-and-answer application consistent with an embodiment of theinvention. As illustrated in FIG. 2, in some embodiments, aquestion-and-answer application is implemented as a web-basedapplication having application logic 30 residing at one or moreprocessor-based computer servers 32. At least some of the servers 32include a web server 34 component for serving data (e.g., documents) toa conventional web browser application 36 residing and executing at aclient computer 38.

As illustrated in FIG. 2, a client computer 38 executes a web browserapplication 36 to access the web-based question-and-answer application.In various alternative embodiments, the client computer 38 may be amobile computing device, to include, a laptop, mobile phone or tabletcomputer. As such, in some embodiments, the application may have aninterface that is customized for display in a browser of a mobiledevice. However, in some embodiments, the client-based application maynot be browser-based, but instead may be customized to suit theparticular operating system of the device on which it is executing. Forinstance, a customized application may utilize one or more applicationprogramming interfaces that are unique to the particular device andoperating system on which the customized application resides andexecutes.

The question-and-answer application logic 30 is shown in FIG. 2 toinclude content posting logic 44, topic merge (and unmerge) logic 46,and question merge (and unmerge) logic 48. The content posting logic 44enables users to post questions, answers and comments. The topic merge(and unmerge) logic 46 facilitates the merging of topics, while thequestion merge logic 48 facilitates the merging of questions. Of course,the application logic 40 may include a number of other logicalcomponents to perform a variety of other tasks and functions beyond theimmediate scope of the present inventive subject matter. As such, toavoid obscuring the inventive subject matter in unnecessary detail,these various functional components are not shown in FIG. 2.

In some embodiments, some of the various functional components of thequestion-and-answer application, including some of the various softwaremodules, may be distributed across several server computers, providingapplication reliability and scalability. For instance, as illustrated inFIG. 2, the database management server 40 is shown to reside on aseparate server computer. However, in other embodiments the databasemanagement server 40 might reside and execute at the same server as theapplication logic 32 and web server 34. In any case, the databasemanagement server 40 facilitates the writing and reading of data storedin tables of a database 42, some of which are described in connectionwith the description of FIG. 3. In some alternative embodiments, otherdata structures may be utilized in addition to, or in place of, databasetables.

FIG. 3 shows some example data structures—in the form of databasetables—for use in implementing a question-and-answer applicationconsistent with an embodiment of the invention. The database tablesshown in FIG. 3 are provided as an example of one particular embodimentof the invention, and are not meant to limit the invention to anyparticular implementation. Accordingly, the exact arrangement ofdatabase tables shown in FIG. 3, including the naming conventions fortables and columns, are provided as examples and are meant to convey anunderstanding of the inventive subject matter, and one particularcontext in which the inventive subject matter might be implemented,without limiting the invention. Moreover, it will be readily appreciatedby skilled artisans that various other tables (not shown in FIG. 3)might be utilized to implement various aspects of a question-and-answerapplication that is consistent with embodiments of the inventive subjectmatter described herein.

As illustrated in FIG. 3, three primary tables are shown along with avariety of other tables used in implementing a question-and-answerapplication, consistent with embodiments of the invention. The threeprimary tables include the QUESTION table 50, the USER table 52 and theTOPIC table 54. The QUESTION table 50 includes fields for storingvarious information about questions, including a QUESTION_ID field forstoring a question identifier to uniquely identify a question, a USERfield to store a user identifier uniquely identifying the particularuser who posted the question, a TIME field to store a time indicatingwhen the question was posted, a TEXT field to store the exact text ofthe question, and various other fields for storing certain attributes ofa question. The USER table 52 includes a USER_ID field for storing anuser identifier for each user of the application, a NAME field forstoring the actual name of a user, a TIME field for storing the dateand/or time when the user became a member of the site, and an ABOUT_MEfield for storing a brief description of the user. The TOPIC tableincludes a TOPIC_ID field for storing a topic identifier that uniquelyidentifies a topic, a TIME field that indicates when the topic wasgenerated, a NAME field for storing the actual name of the topic, and aMERGED_TO_TOPIC_ID field that stores a topic identifier of another topicinto which a topic has been merged.

A variety of other supporting tables are also shown in FIG. 3, toinclude a QUESTION_TOPIC table 56 that maps questions to topics, aUSER_TOPIC table 58 that maps users to topics, a QUESTION_FOLLOW table60 that identifies the particular topics that each user is following,and a USER_FOLLOW table 62 that identifies the particular users thateach user is following. In addition, FIG. 3 includes an ANSWER table 64that includes fields for storing various attributes of an answer to aquestion, including the question identifier of the particular questioncorresponding with the answer, the actual text of the answer, the useridentifier of the user who posted the answer, and the time at which theanswer was posted.

An OPERATION table 66 includes various fields for storing informationthat handles various version control features. For example, theOPERATION table 66 has an OPERATION_ID field for storing an operationidentifier, a TYPE field for storing an operation type, a DATA field forstoring data relevant to a particular operation, a TIME field toindicate the time the operation was successfully completed, a USER_IDfield to store the user identifier of the user who initiated theoperation, and a REVERT_OPERATION_ID to store an operation identifierfor an operation that was completed to revert a previous operation.Using this information, various operations having different operationtypes can be reverted, such that the operation is effectively undone.For example, one particular operation type involves merging one topicinto another topic. When a topic merge operation is successfullycompleted, a record will be generated in the OPERATION table 66. If itbecomes necessary to undo the topic merge operation, the relevant datain the record can be utilized to simply undo the topic merge operation.

In some embodiments, a user can participate anonymously. Accordingly,the QUESTION_PRIVACY table 68 stores information to indicate whether auser's identification information (e.g., name) should be displayed inconnection with a particular question.

As briefly described above, in some embodiments users can vote up orvote down answers to questions. Accordingly, the ANSWER_DOWNVOTE table70 and the ANSWER_VOTE table 72 include fields for storing votinginformation for different questions, to include the user identifier ofthe user who voted up or down a particular answer. Such information canbe used in various algorithms designed to determine how best to presentanswers to users.

FIG. 4 is a user interface diagram illustrating an example of a userinterface for use with a question-and-answer application consistent withan embodiment of the invention. As with the various tables illustratedin FIG. 3, the example user interface shown in FIG. 4 is provided toconvey an understanding of the inventive concepts described herein, anda particular context in which the inventive subject matter might beimplemented. It will be readily appreciated by those skilled in the artthat the example user interface is but one example of a user interface.

As illustrated in FIG. 4, a header or banner section 74 is shown toinclude a text input box 76 where a user can enter a question, oralternatively, enter one or more keywords to be used in a search for aquestion. Under the header section 74 is a portion of the user interfaceshowing a question 78, and several topics 80 to which the question iscurrently assigned. For instance, in this example, the question is:“What are the most popular rides at Disneyland?” The topics 80 to whichthe question has been assigned include: “Amusement Parks,” “Disneyland,”“Family Vacations,” and “Vacation.” Next to the topics is a link (or,button) 82 enabling a user to add a new topic to be associated withquestion. In addition, a separate button or link 84, shown in FIG. 4with text “Add Question Details” provides the user with the ability toenter additional details about the question. Separate buttons or linksexist for other user functionality, such as adding comments about thequestion, adding a follow-up question and flagging the question, forexample, as being inappropriate.

In this example user interface, beneath the question 78 are threeanswers 86, 88 and 90 provided by three different users. Associated witheach question is a name of the user who posted the answer, along with anindication of the number of people following that user. For example, thefirst answer 86 was posted by the user, John Smith, while the secondanswer 88 was posted by Kate Johansen, and the third answer 90 byElliott Adams. Beneath each respective answer are buttons or links thatenable a user to add a comment about an answer, or indicate that ananswer was helpful or not helpful. In addition, to the left of eachanswer are two arrows for use in voting. For example, the arrow buttons(up and down) for the answer posted by John Smith have reference number92.

At the bottom of the example user interface in FIG. 4, there is a textbox 94 providing a user with the ability to submit a new answer to thequestion 78. For example, a user can type an answer in the text box 94and then hit the SUBMIT ANSWER 96 button to post the answer to thequestion-and-answer application. To make an answer anonymous, such thatthe posting user's name will not be displayed next to the answer, ananonymous button or link 98 is provided.

FIG. 5 is a block diagram showing an example of how database tables canbe utilized in a topic merge operation to merge two topics with oneanother, consistent with an embodiment of the invention. Morespecifically, the examples presented in FIGS. 5 and 6 show how a firsttopic can be merged into a second (target) topic. In FIG. 5, twoseparate tables are shown—a QUESTION TOPIC table 100 and a TOPIC table102. The QUESTION TOPIC table 100 maps a question to a particular topic,and as such, has three columns—a QUESTION_ID column, a TOPIC_ID column,and a TIME column. Accordingly, each record in the QUESTION TOPIC tableconsists of a question identifier that uniquely identifies a question, atopic identifier to identify a topic to which the question with thecorresponding QUESTION_ID is associated, and a time at which thequestion was assigned to, or associated with, the corresponding topic.For instance, the record with reference number 104 indicates that thequestion with question identifier, “Q1”, is associated with the topichaving topic identifier, “A”, and that the association was made on Jan.1, 2010 at 9:05.

The relationship diagram 106 provides a visual representation of therelationships between the question with question identifier, “Q1”, andvarious topics, as set forth by the data shown in the example QUESTIONTOPIC table 100 of FIG. 5. In particular, the relationship diagram 106shows that the topics with topic identifiers “A”, “B”, “C” and “D” areall assigned to, or associated with, the question with questionidentifier “Q1”.

The TOPIC table 102 maps topics to their respective topic names. Inaddition, when a topic has been merged into another topic, thisrelationship is reflected in the TOPIC table 102. For instance, theTOPIC table maps a topic identifier (e.g., “A”) to an actual topic name(e.g., “San Francisco Bay Area”), and indicates whether the topic hasbeen merged into another topic. As shown in FIG. 5, the TOPIC tableincludes four columns, including a TOPIC_ID column, a TIME column, aNAME column, and a MERGED_INTO_TOPIC_ID column. A topic identifier, ifpresent in the MERGED_INTO_TOPIC_ID field 108, indicates the particulartopic into which a topic has been merged. As such, a record in the TOPICtable 102 indicates a topic identifier for identifying a topic, the timeat which the topic was first generated, the actual name of the topic,and a field—the MERGED_INTO_TOPIC_ID field 108—to indicate whether thetopic has been merged into another target topic, and the topicidentifier of that target topic.

The relationship diagram 110 associated with the TOPIC table 102provides a visual representation of the relationships set forth by thedata in the TOPIC table 102. Specifically, from the relationship diagram110, it is easy to see that the topic, “The Bay Area,” with topicidentifier, “B”, has been merged into the topic, “The Greater Bay Area,”with topic identifier, “A”. Similarly, the topic with topic identifier“C” has been merged into the topic with topic identifier “X”. The topicsthat correspond with topic identifiers “A” and “D” respectively have notbeen merged into other topics.

As will be described in greater detail below, when a user requests thata particular topic be merged with another topic, the topic merge logic46 processes the request by simply writing the topic identifier of thetarget topic in the MERGED_INTO_TOPIC_ID field 108 of the particulartopic that is being merged. For instance, to merge the topic, “SanFrancisco,” with topic identifier “D” into the topic, “San Francisco BayArea,” with topic identifier “A”, the topic merge logic 46 would simplywrite the topic identifier for the topic, “San Francisco Bay Area”(i.e., TOPIC_ID=“A”) in the MERGED_INTO_TOPIC_ID field of the relevantrecord for the topic, “San Francisco”.

FIG. 6 is a flow diagram illustrating method operations involved in amethod to merge one topic with another, consistent with an embodiment ofthe invention. At method operation 112, a request is received to merge afirst topic with a second (target) topic. Specifically, the requestindicates that a first topic should be merged into the second (target)topic. As such, at a minimum, the request identifies a first topic and asecond target topic into which the first topic is to be merged. Therequest may be received (e.g., by the topic merge logic 46) as a resultof a user or administrator, manipulating one or more elements of agraphical user interface. For instance, a user may select a button toedit or manage a first particular topic, and in response, the user maybe presented with a web page having another button that initiates atopic merge operation. When this second button is selected, the user maybe presented with a list of topics from which to select the target topicinto which the first particular topic is to be merged. The request tomerge the two topics is thus generated as a result of a user oradministrator manipulating one or more graphical user interface elementsand identifying a first topic that is to be merged, and a target topicinto which the first topic is to be merged.

At method operation 114, the question-and-answer application determineswhether the target topic is currently merged with another topic. Forinstance, the topic merge logic 46 may simply perform a database look-upoperation to determine whether the MERGED_INTO_TOPIC_ID field for thetarget topic is populated with a topic identifier of another topic. Ifthe MERGED_INTO_TOPIC_ID field for the target topic is storing a validtopic identifier for another topic, indicating that the target topic isitself merged into another topic, then at method operation 116, thetopic merge logic 46 merges the first topic into the same topic withwhich the target topic is merged. Specifically, the first topic will bemerged with the topic identified by the topic identifier in theMERGED_INTO_TOPIC_ID field of the target topic.

Referring again to the example TOPIC table 102 illustrated in FIG. 5, ifa request is received to merge the topic, “San Francisco,” with topicidentifier “D” into the topic, “San Francisco, Calif.,” with topicidentifier “C”, the result will be that the topic, “San Francisco,” willnot be merged with the topic, “San Francisco, Calif.”, but will insteadbe merged into the topic, “The Greater Bay Area” with topic identifier,“X”. This topic merge operation will be achieved by simply writing thetopic identifier, “X” into the MERGED_INTO_TOPIC_ID field 108 of therecord for topic, “San Francisco” with topic identifier, “D”.

However, if at method operation 114, it is determined that the targettopic is not merged into another topic, then at method operation 118,the first topic is merged into the second (target) topic by simplywriting the appropriate topic identifier into the appropriate field,which in this example is the MERGED_INTO_TOPIC_ID field. Referring againto the example TOPIC table 102 in FIG. 5, if a request indicates thatthe topic “San Francisco” with topic identifier, “D,” is to be mergedwith the topic, “San Francisco Bay Area,” with topic identifier, “A,”then the topic identifier, “A” is written in the MERGED_INTO_TOPIC_IDfield 108 of the record with reference number 120 to indicate that thetopic “San Francisco” is merged into the topic “San Francisco Bay Area.”After the appropriate record in the TOPIC table 102 has been updated,the topic merge operation is logged in the appropriate logging table ortables to reflect the successful completion of the topic mergeoperation.

FIG. 7 is a flow diagram illustrating method operations involved in amethod to identify and display topics associated with a content item,such as a question or answer in a question-and-answer application,according to an embodiment of the invention. The method illustrated inFIG. 7 may be performed, for example, when a question-and-answerapplication is generating a web page to present to a particular user,such that the web page shows all of the topics associated with aparticular question, or, all of the topics that the particular user isfollowing. As such, the method may be performed in response to a userrequesting, via a client application (e.g., web browser) a web page thatis to include the relevant topics for a question or user.

The method begins at method operation 122 when all of the topicsassociated with a particular question (or user), as indicated in a firstdatabase table, are identified. For example, if all of the topicsassociated with a particular question are to be displayed, the QUESTIONTOPIC table 100 (FIGS. 3 and 5) may be analyzed to identify all of thetopic identifiers that are associated with the question identifier ofthe particular question. By way of example, referring to theQUESTION_TOPIC table 100 of FIG. 5, the completion of method operation122 for the question with question identifier, “Q1”, would result in alist of topic identifiers including, topic “A”, topic “B”, topic “C”,and topic “D”. Similarly, if all of the topics a particular user isfollowing are to be presented, the USER TOPIC Table 58 (FIG. 3) may beanalyzed to identify all of the topic identifiers associated with theuser identifier of the particular user.

In both cases, the list of topics, or topic identifiers to be moreprecise, resulting from method operation 122 may not be the final listof topics as the initial list will not reflect the fact that one or moretopics may have been merged into another topic. As such, at methodoperation 124, for each topic that was identified in method operation122, a “follow-merge” operation is performed. A follow-merge operationmay be performed by follow-merge logic that is implemented as a functionor sub-routine that is part of the topic merge logic 46, or as astandalone function or subroutine that is called by the topic mergelogic 46. In either case, the follow-merge logic receives as input aparticular topic identifier, and returns either the topic identifier ofanother topic—indicating the topic corresponding to the input topicidentifier has been merged into another topic—or, the same topicidentifier that was received as input, indicating that the topicassociated with the received input topic identifier has not been mergedinto another topic. An example method of a “follow-merge” operation isshown in FIG. 8.

Referring to FIG. 8, at method operation 126, a topic identifier isreceived (e.g., by the follow-merge logic) for a particular topic. Atmethod operation 128, the follow-merge logic determines whether thetopic associated with the received topic identifier has been merged intoanother topic. For example, this may involve reading or otherwiseanalyzing the MERGED_INTO_TOPIC_ID field of the record in the TOPICtable 102 corresponding to the input topic identifier. If theMERGED_INTO_TOPIC_ID field contains a valid topic identifier, thisindicates that the topic corresponding to the received topic identifierhas previously been merged into another topic. Accordingly, at methodoperation 130, the follow-merge logic returns the topic identifier ofthe topic into which the received topic (topic identifier) has beenmerged. However, if the MERGED_INTO_TOPIC_ID field does not contain atopic identifier, then it is presumed that the topic corresponding withthe received topic identifier has not previously been merged intoanother topic. Referring briefly to the TOPIC table 102 in FIG. 5, ifthe follow-merge operation is invoked for the topic, “San Francisco BayArea” with topic identifier “A” (e.g., the record with reference number134), the follow-merge operation would return topic identifier, “A”indicating that the topic, “San Francisco Bay Area” has not previouslybeen merged with another topic. On the other hand, if the follow-mergeoperation is invoked for the topic, “The Bay Area” with topic identifier“B” (e.g., the record with reference number 136), the follow-mergeoperation would return topic identifier, “X” indicating that the topic,“The Bay Area” has previously been merged with the topic, “The GreaterBay Area” with topic identifier, “X”.

Returning now to the method illustrated in FIG. 7, once the follow-mergeoperation has been performed for each topic identifier that wasdetermined to be associated with the question (or, user), at methodoperation 138, all duplicate topic identifiers are eliminated. Forexample, because some topics may have been merged into others, the listof topic identifiers generated by the follow-merge operation may includeduplicates. Accordingly, the duplicate topic identifiers are identifiedand removed from the resulting list of topic identifiers. By way ofexample, referring again to the TOPIC table 102 in FIG. 5, the list oftopic identifiers resulting from method operation 124 would includetopic identifiers, “A”, “A”, “X”, and “D”. After removing duplicates,the final list would include topic identifiers, “A”, “X”, and “D”.

Finally, at method operation 140, the list of topic identifiersresulting from method operation 138 are provided to the appropriateapplication logic for processing and display to a user. For example, thelist of topic identifiers may be used to query one or more otherdatabase tables for related information, which is then collectively usedin the generation of a web page that is served to a client application,such as a web browser application, of a user.

FIG. 9 is a flow diagram illustrating method operations involved in amethod to identify content items (e.g., questions or users) to which aparticular topic is associated. This method might be performed, forexample, when a user requests to see all of the questions associatedwith a particular topic, or, all of the users following a particulartopic. The method begins at operation 142 when a request for allquestions (or, users) associated with a particular topic is received,and in response, all topics that have been merged into the particulartopic are identified. For example, to identify the relevant topics, thetopic identifier for the requested topic must first be identified, andthen all topics having the topic identifier of the requested topic inthe MERGED_INTO_TOPIC_ID field (column 108 in FIG. 5), indicating thatthe particular corresponding topic has been merged with the requestedtopic. Referring to the TOPIC table 102 in FIG. 5, if the request is forall questions associated with the topic, “San Francisco Bay Area,” withtopic identifier “A”, then the TOPIC table 102 is read to identify thetopic identifier for the topic, “San Francisco Bay Area”—in this case,topic identifier, “A”. Next, any records that have the topic identifier,“A” in the MERGED_INTO_TOPIC_ID field 108 are identified. In thisexample, the record with reference number 136 indicates that the topic,“The Bay Area” with topic identifier, “B” has been merged into the topic“San Francisco Bay Area,” with topic identifier “A”.

After the relevant topic identifiers have been identified—including thetopic identifier for the requested topic and the topic identifiers forany topics that have been merged into the requested topic—at methodoperation 144, the questions (or, users) associated with the relevanttopic identifiers are identified. For example, using the relevant topicidentifiers, the appropriate table can be queried to identify thequestions (or, users) that are associated with the various topicidentifiers. Referring to FIG. 3, the QUESTION TOPIC table 56 might bequeried to identify the questions related to the various topicidentifiers. Similarly, the USER TOPIC table 58 might be queried if theinitial request is for all users associated with a particular topic.

Next, at method operation 146, the questions (or, users) determined tobe related to the various topic identifiers identified at methodoperation 142 are merged. Finally, at method operation 148, the mergedlist of questions (or, users) is provided to the relevant applicationlogic component for further processing and display to a user.

The various operations of example methods described herein may beperformed, at least partially, by one or more processors that aretemporarily configured (e.g., by software) or permanently configured toperform the relevant operations. Whether temporarily or permanentlyconfigured, such processors may constitute processor-implemented modulesthat operate to perform one or more operations or functions. The modulesor logical components referred to herein may, in some exampleembodiments, comprise processor-implemented modules or logic.

Similarly, the methods described herein may be at least partiallyprocessor-implemented. For example, at least some of the operations of amethod may be performed by one or more processors orprocessor-implemented modules. The performance of certain of theoperations may be distributed among the one or more processors, not onlyresiding within a single machine, but deployed across a number ofmachines. In some example embodiments, the processor or processors maybe located in a single location (e.g., within a home environment, anoffice environment or as a server farm), while in other embodiments theprocessors may be distributed across a number of locations.

The one or more processors may also operate to support performance ofthe relevant operations in a “cloud computing” environment or as a“software as a service” (SaaS). For example, at least some of theoperations may be performed by a group of computers (as examples ofmachines including processors), these operations being accessible via anetwork (e.g., the Internet) and via one or more appropriate interfaces(e.g., Application Program Interfaces (APIs).)

FIG. 10 is a block diagram of a machine in the form of a computer withinwhich a set of instructions, for causing the machine to perform any oneor more of the methodologies discussed herein, may be executed. Inalternative embodiments, the machine operates as a standalone device ormay be connected (e.g., networked) to other machines. In a networkeddeployment, the machine may operate in the capacity of a server or aclient machine in server-client network environments, or as a peermachine in peer-to-peer (or distributed) network environments. Themachine may be a personal computer (PC), a tablet PC, a set-top box(STB), a Personal Digital Assistant (PDA), a mobile telephone, a webappliance, a network router, switch or bridge, or any machine capable ofexecuting instructions (sequential or otherwise) that specify actions tobe taken by that machine. Further, while only a single machine isillustrated, the term “machine” shall also be taken to include anycollection of machines that individually or jointly execute a set (ormultiple sets) of instructions to perform any one or more of themethodologies discussed herein.

The example computer system 1500 includes a processor 1502 (e.g., acentral processing unit (CPU), a graphics processing unit (GPU) orboth), a main memory 1501 and a static memory 1506, which communicatewith each other via a bus 1508. The computer system 1500 may furtherinclude a display unit 1510, an alphanumeric input device 1517 (e.g., akeyboard), and a user interface (UI) navigation device 1511 (e.g., amouse). In one embodiment, the display, input device and cursor controldevice are a touch screen display. The computer system 1500 mayadditionally include a storage device (e.g., drive unit 1516), a signalgeneration device 1518 (e.g., a speaker), a network interface device1520, and one or more sensors 1521, such as a global positioning systemsensor, compass, accelerometer, or other sensor.

The drive unit 1516 includes a machine-readable medium 1522 on which isstored one or more sets of instructions and data structures (e.g.,software 1523) embodying or utilized by any one or more of themethodologies or functions described herein. The software 1523 may alsoreside, completely or at least partially, within the main memory 1501and/or within the processor 1502 during execution thereof by thecomputer system 1500, the main memory 1501 and the processor 1502 alsoconstituting machine-readable media.

While the machine-readable medium 1522 is illustrated in an exampleembodiment to be a single medium, the term “machine-readable medium” mayinclude a single medium or multiple media (e.g., a centralized ordistributed database, and/or associated caches and servers) that storethe one or more instructions. The term “machine-readable medium” shallalso be taken to include any tangible medium that is capable of storing,encoding or carrying instructions for execution by the machine and thatcause the machine to perform any one or more of the methodologies of thepresent invention, or that is capable of storing, encoding or carryingdata structures utilized by or associated with such instructions. Theterm “machine-readable medium” shall accordingly be taken to include,but not be limited to, solid-state memories, and optical and magneticmedia. Specific examples of machine-readable media include non-volatilememory, including by way of example semiconductor memory devices, e.g.,EPROM, EEPROM, and flash memory devices; magnetic disks such as internalhard disks and removable disks; magneto-optical disks; and CD-ROM andDVD-ROM disks.

The software 1523 may further be transmitted or received over acommunications network 1526 using a transmission medium via the networkinterface device 1520 utilizing any one of a number of well-knowntransfer protocols (e.g., HTTP). Examples of communication networksinclude a local area network (“LAN”), a wide area network (“WAN”), theInternet, mobile telephone networks, Plain Old Telephone (POTS)networks, and wireless data networks (e.g., Wi-Fi® and WiMax® networks).The term “transmission medium” shall be taken to include any intangiblemedium that is capable of storing, encoding or carrying instructions forexecution by the machine, and includes digital or analog communicationssignals or other intangible medium to facilitate communication of suchsoftware.

Although an embodiment has been described with reference to specificexample embodiments, it will be evident that various modifications andchanges may be made to these embodiments without departing from thebroader spirit and scope of the invention. Accordingly, thespecification and drawings are to be regarded in an illustrative ratherthan a restrictive sense. The accompanying drawings that form a parthereof, show by way of illustration, and not of limitation, specificembodiments in which the subject matter may be practiced. Theembodiments illustrated are described in sufficient detail to enablethose skilled in the art to practice the teachings disclosed herein.Other embodiments may be utilized and derived therefrom, such thatstructural and logical substitutions and changes may be made withoutdeparting from the scope of this disclosure. This Detailed Description,therefore, is not to be taken in a limiting sense, and the scope ofvarious embodiments is defined only by the appended claims, along withthe full range of equivalents to which such claims are entitled.

What is claimed is:
 1. A computer-implemented method to merge topicsassociated with a content item of an online application, the methodcomprising: receiving a request to merge a first topic with a secondtopic, the first and second topics stored as separate records in adatabase table, each record having a first field to store a topicidentifier that identifies its respective topic and a second field tostore a topic identifier into which the respective topic has beenmerged; and responsive to reading the second field of the record for thesecond topic to determine that the second topic has not been merged withanother topic, using processor-implemented topic merge logic to writethe topic identifier of the second topic into the second field of therecord for the first topic to indicate that the first topic has beenmerged into the second topic, wherein removal of the topic identifierfrom the second field of the record of the first topic undoes the merge.2. The computer-implemented method of claim 1, further comprising: uponsuccessfully writing the topic identifier of the second topic into thesecond field of the record for the first topic to indicate that thefirst topic has been merged into the second topic, updating a databasetable with operation logging information that allows the merge to beundone.
 3. The computer-implemented method of claim 1, wherein thecontent item is a question of a question-and-answer application and thefirst and second topics are associated with one or more questions of thequestion-and-answer application and designate a subject matter relatedto the one or more questions.
 4. A processing system comprising: atleast one processor; and a machine-readable medium in communication withthe at least one processor, the machine readable medium storingapplication logic including topic merge logic that is executable by theat least one processor, the application logic being executed by the atleast one processor to cause operations to be performed, the operationscomprising: receiving a request to merge a first topic with a secondtopic, the first and second topics stored as separate records in adatabase table, each record having a first field to store a topicidentifier that identifies its respective topic and a second field tostore a topic identifier into which the respective topic has beenmerged; and responsive to reading the second field of the record for thesecond topic to determine that the second topic has not been merged withanother topic, writing the topic identifier of the second topic into thesecond field of the record for the first topic to indicate that thefirst topic has been merged into the second topic, wherein removal ofthe topic identifier from the second field of the record of the firsttopic undoes the merge.
 5. The processing system of claim 4, wherein theoperations further comprise: upon successfully writing the topicidentifier of the second topic into the second field of the record forthe first topic to indicate that the first topic has been merged intothe second topic, updating a database table with operation logginginformation that allows the merge to be undone.
 6. The processing systemof claim 4, wherein the topic merge logic is to prevent the first topicfrom being merged into the second topic when the second field of therecord for the second topic contains a topic identifier of a thirdtopic, indicating that the second topic has been merged into the thirdtopic.
 7. A computer-implemented method to merge topics associated witha content item of an online application, the method comprising:receiving a request to merge a first topic with a second topic, thefirst and second topics stored as separate records in a database table,each record having a first field to store a topic identifier thatidentifies its respective topic and a second field to store a topicidentifier into which the respective topic has been merged; andresponsive to reading the second field of the record for the secondtopic to determine that the second topic has been merged with a thirdtopic, using processor-implemented topic merge logic to write a topicidentifier of the third topic into the second field of the record forthe first topic to indicate that the first topic has been merged intothe third topic, wherein removal of the topic identifier from the secondfield of the record of the first topic undoes the merge.
 8. Thecomputer-implemented method of claim 7, further comprising: uponsuccessfully writing the topic identifier of the third topic into thesecond field of the record for the first topic to indicate that thefirst topic has been merged into the third topic, updating a databasetable with operation logging information that allows the merge to beundone.
 9. The computer-implemented method of claim 7, wherein thecontent item is a question of a question-and-answer application, and thefirst, second and third topics are associated with one or more questionsof the question-and-answer application and designate a subject matterrelated to the one or more questions.
 10. A processing systemcomprising: at least one processor; and a machine-readable medium incommunication with the at least one processor, the machine readablemedium storing application logic including topic merge logic that isexecutable by the at least one processor, the application logic beingexecuted by the at least one processor to cause operations to beperformed, the operations comprising: receiving a request to merge afirst topic with a second topic, the first and second topics stored asseparate records in a database table, each record having a first fieldto store a topic identifier that identifies its respective topic and asecond field to store a topic identifier into which the respective topichas been merged; responsive to reading the second field of the recordfor the second topic to determine that the second topic has been mergedwith a third topic, writing a topic identifier of the third topic intothe second field of the record for the first topic to indicate that thefirst topic has been merged into the third topic, wherein removal of thetopic identifier from the second field of the record of the first topicundoes the merge.
 11. The processing system of claim 10, wherein theoperations further comprise: upon successfully writing the topicidentifier of the third topic into the second field of the record forthe first topic to indicate that the first topic has been merged intothe third topic, updating a database table with operation logginginformation that allows the merge to be undone.
 12. The processingsystem of claim 10, wherein the topic merge logic is to prevent thefirst topic from being merged into the second topic when the secondfield of the record for the second topic contains a topic identifier ofa third topic, indicating that the second topic has been merged into thethird topic.
 13. A computer-implemented method comprising: receiving ata question-and-answer application a request to display a content itemwith which one or more topics are associated; identifying a first set oftopics by performing a first look-up operation with a first databasetable to identify topics associated with the content item as indicatedin the first database table; identifying a second set of topics byperforming a second look-up operation with a second database table, thesecond look-up operation to identify any topics into which a topic inthe first set of topics has been merged based, at least in part, on atopic identifier of the first set of topics as included in the seconddatabase table, wherein removal of the topic identifier from the seconddatabase table undoes the merge; providing the second set of topics toapplication logic for further processing and presentation in a web page.14. The computer-implemented method of claim 13, further comprising:removing any duplicate topics from the second set of topics prior toproviding the second set of topics to the application logic.
 15. Thecomputer-implemented method of claim 13, wherein the request is for aquestion to which the topics are associated.
 16. A processing systemcomprising: at least one processor; and a machine-readable medium incommunication with the at least one processor, the machine readablemedium storing question-and-answer application logic that is executableby the at least one processor, the application logic being executed bythe at least one processor to cause operations to be performed, theoperations comprising: receiving a request to display a content itemwith which one or more topics are associated; identifying a first set oftopics by performing a first look-up operation with a first databasetable to identify topics associated with the content item as indicatedin the first database table; identifying a second set of topics byperforming a second look-up operation with a second database table, thesecond look-up operation to identify any topics into which a topic inthe first set of topics has been merged based, at least in part, on atopic identifier of the first set of topics as included in the seconddatabase table, wherein removal of the topic identifier from the seconddatabase table undoes the merge; and providing the second set of topicsto application logic for further processing and presentation in a webpage.
 17. The processing system of claim 16, wherein the operationsfurther comprise: removing any duplicate topics from the second set oftopics prior to providing the second set of topics to the applicationlogic.
 18. The processing system of claim 16, wherein the request is fora question to which the topics are associated.